“Hardiness” is a term that comes up a lot in crop and flower research.
It refers to a plant or crop’s hardiness zone, growing zone, or planting zone.
There are different climate zones in which a particular plant can survive. Some plants can survive in very cold zones, very hot zones, moderate zones, or the majority of them.
There are currently 13 zones.
Each zone has a 10 degree difference. Within each zone, there are subzones A and B that divide the zone by a 5 degree difference. All of the temperatures that make up the zones are decided by those areas’ average annual minimum winter temperature.
The continental United States does not go above zone 11a, which reaches an average 45 degrees. However, Hawaii and Puerto Rico both reach zone 13, achieving average winter temperatures of 70 degrees.
On the opposite side of the temperature spectrum, Alaska is the only state to reach the frigid zones of both 1 and 2 at -60 degrees in some areas! Zone 3 is the coldest that the continental U.S. will experience in its most northern parts, at -40 degrees. Due to the size and location of the United States in reference to the equator, there are many different climates and zones that impact what you can successfully grow.
In general, the farther north you are the colder the zone; and the farther south, the warmer the zone.
Depending on other small factors, you could live in what is called a microclimate. Living next to a body of water can cause the water to store heat when it is warm and release when the temperature drops through heat transfer. Living next to large buildings or a treeline can deter wind and increase moisture in the air.
While these zones can certainly give you an idea of what to plant in your area, think about what factors are in your direct vicinity. The USDA map allows you to put your zip code into the map to see which of the 13 hardiness zones you currently live in.
Cold Hardiness Zones
If you reside in a cold-hardy region, there a few beautiful flowers to consider.
Delphiniums are a tall and bold blue or purple flower that blooms in the summer and thrives in zones 3 through 7. Along with their striking presence, they have the added plus of attracting butterflies!
Peonies are another wonderful flower to add to your garden; they are full of body and color. They come in red, pink, white, and yellow and thrive in zones 3 through 8. They bloom earlier than delphiniums in the springtime.
Hot Hardiness Zones
Stunning plants can thrive in the hotter zones as well.
Canna lilies are exotic and bright. They bloom in the summer and fall and come in orange, pink, red, white, and yellow. These lilies live in zones 8 to 11.
An extremely easy and unique-looking plant to care for is the ponytail palm. It thrives in zones 9 through 11 and will be around for most of your life, as long as you don’t overwater it!
Knowing the hardiness zones will help you to better understand what you can and cannot grow in your area. Once you know your zone, you can focus on bigger issues like soil and irrigation. What hardiness zone do you live in?